Indians celebrate the International Day of Older Persons in Ahmadabad, India. A global study says that by the year 2050, those older than 60 will outnumber those younger than 15 for the first time.

The report ranks the social and economic well-being of elders in 91 countries, with Sweden coming out on top and Afghanistan at the bottom. It reflects what advocates for the old have been warning, with increasing urgency, for years: Nations are simply not working quickly enough to cope with a population graying faster than ever before.

By the year 2050, for the first time in history, seniors older than 60 will outnumber those younger than 15.

Truong Tien Thao, who runs a small tea shop on the sidewalk near his home in Hanoi, Vietnam, is 65 and acutely aware that he, like millions of others, is plunging into old age without a safety net.

He wishes he could retire, but he and his 61-year-old wife depend on the $50 a month they earn from the shop. And so every day, Thao rises early to open the stall at 6 a.m. and works until 2 p.m., when his wife takes over until closing.

“People at my age should have a rest, but I still have to work to make our ends meet,” he said while waiting for customers at the shop, which sells green tea, cigarettes and chewing gum. “My wife and I have no pension, no health insurance. I’m scared of thinking of being sick – I don’t know how I can pay for the medical care.”

Perhaps surprisingly, the report shows the fastest aging countries are developing ones, such as Jordan, Laos, Mongolia, Nicaragua and Vietnam, where the number of older people will more than triple by 2050. All ranked in the bottom half of the index.

The Global AgeWatch Index was created by elder advocacy group HelpAge International and the U.N. Population Fund in part to address a lack of international data on the extent and impact of global aging. The index compiles data from the U.N., World Health Organization, World Bank and other global agencies, and analyzes income, health, education, employment and age-friendly environment in each country.

THE INDEX WAS welcomed by elder rights advocates, who have long complained that a lack of data has thwarted attempts to raise the issue on government agendas.

“Unless you measure something, it doesn’t really exist in the minds of decision-makers,” said John Beard, the director of Ageing and Life Course for the World Health Organization. “One of the challenges for population aging is that we don’t even collect the data, let alone start to analyze it. … For example, we’ve been talking about how people are living longer, but I can’t tell you people are living longer and sicker, or longer in good health.”

The report fits into an increasingly complex picture of aging and what it means to the world.

On the one hand, the fact that people are living longer is a testament to advances in health care and nutrition, and advocates emphasize that the elderly should be seen not as a burden but as a resource. On the other, many countries still lack a basic social protection floor that provides income, health care and housing for their senior citizens.

Many governments have resisted tackling the issue partly because it is viewed as hugely complicated, negative and costly – which is not necessarily true, said Silvia Stefanoni, the chief executive of HelpAge International. Japan and Germany, she said, have among the highest proportions of elders in the world, but also boast steady economies.

“There’s no evidence that an aging population is a population that is economically damaged,” she said.

Prosperity in itself does not guarantee protection for the old. The world’s rising economic powers – Brazil, Russia, India, China and South Africa – rank lower in the index than some poorer countries such as Uruguay and Panama.

However, the report found, wealthy nations are in general better prepared for aging than poorer ones. Sweden, where the pension system is now 100 years old, makes the top of the list because of its social support, education and health coverage. It is followed by Norway, Germany, the Netherlands and Canada. The U.S. comes in eighth.

Still, even in an elder-friendly country such as Sweden, aging is not without its challenges. The Swedish government has suggested people continue working beyond 65.